| In millions, except per share items | Mar-31-22 | Dec-31-21 | Sep-30-21 | Mar-31-21 | Dec-31-20 | Sep-30-20 | Jun-30-20 | Jun-05-20 |
| | 10-Q | 10-K | 10-Q | 10-Q | 10-K | 10-Q | 10-Q | 8-K |
| Service revenue | 0.1 | 0.1 | 0.3 | 0.3 | 0.2 | | | 4.9 |
| Service revenue growth | -48.8% | -61.2% | | | | | | -25.7% |
| Operating expenses: | | | | | | | | |
| Cost of service revenue | 0.1 | 0.1 | 0.3 | 0.2 | | | | |
| Research and development | 4.5 | 4.7 | 6.0 | 5.3 | 5.4 | 5.8 | 4.9 | |
| General and administrative | 2.9 | 2.3 | 2.5 | 2.8 | 2.6 | 2.7 | 2.8 | 2.8 |
| Impairment loss | 25.9 | | | | | | | |
| Total operating expenses | 33.5 | 7.0 | 8.8 | 8.3 | 8.2 | 8.5 | | |
| Loss from operations | -33.3 | -6.9 | -8.6 | -8.0 | -7.9 | -8.5 | -7.7 | -7.7 |
| Operating margin | -25240.9% | -7950.6% | -3410.7% | -3119.4% | | | | -156.1% |
| |
| Other income (expense): | | | | | | | | |
| Interest income | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Interest expense | -0.1 | -0.1 | 0.0 | -0.1 | -0.2 | -0.2 | -0.2 | -0.2 |
| Other income (expense), net | 0.0 | 0.0 | -0.1 | 0.0 | 0.0 | 0.0 | 0.0 | |
| Loss before provision for income taxes | -33.4 | -7.0 | -8.7 | -8.1 | -8.1 | -8.7 | -7.9 | |
| Provision for income taxes | | | | | | | | |
| Net loss | -33.4 | -7.0 | -8.7 | -8.1 | -8.1 | -8.7 | -7.9 | -7.9 |
| |
| Net loss per common share - basic (in USD per share) | ($7.86) | ($0.06) | ($0.07) | ($2.73) | ($0.04) | ($0.11) | ($0.14) | ($0.14) |
| Net loss per common share - diluted (in USD per share) | ($7.86) | ($0.06) | ($0.07) | ($2.73) | ($0.04) | ($0.11) | ($0.14) | ($0.14) |
| |
| Weighted-average common shares used in computing net loss per common share – basic | 4.2 | 112.1 | 115.8 | 3.0 | 67.9 | 77.9 | 54.9 | 54.9 |
| Weighted-average common shares used in computing net loss per common share – diluted | 4.2 | 112.1 | 115.8 | 3.0 | 67.9 | 77.9 | 54.9 | 54.9 |
| |
| Revenue from Contract with Customer, Product and Service [Extensible List] | | | | | | | | |
| Cost, Product and Service [Extensible List] | | | | | | | | |